Otto-von-Guericke University Magdeburg

After a deep analysis of the different problems related to lexical resources and in particular to WordNet and its variations, I decided to convert EuroWordNet, the much richer multilingual WordNet variant, into an RDF/OWL representation. The decision of converting EuroWordNet was based on the need of extending it (because not all meanings are covered) with other resources. These resources are domain-specific and could enhance the coverage of meanings used for the semantic classification of the documents (as I discussed in my doctoral thesis). The novelty of this approach is to extend the monolingual WordNet RDF/OWL representation for a multilingual purpose, but also for a possible domain-specific extension, because most domain-specific ontologies are written in OWL.
Together with Aldo Gangemi (the Laboratory of applied ontologies in Rom, Italy), I am working on the possibility to integrate my multilingual RDF/OWL EuroWordNet representation into the standardized W3C RDF/OWL representation of WordNet.
Together with Birte Lönneker-Rodman (International Computer Science Institute der University of California, Berkeley), I am now exploring possibilities to convert the Hamburg Metaphor Database into my RDF/OWL Format.

This project was part of European Network of Excellence on Intelligent Technologies for Smart Adaptive Systems (EUNITE) to review the state of the art in user adaptive search interfaces and to initiate and intensify research collaboration between different research communities and the industry. During the last years several approaches have been developed that tackle specific problems of the retrieval process, e.g. feature extraction methods for multimedia data, problem specific similarity measures and interactive user interfaces. These methods enable the design of efficient retrieval tools if the user is able to provide an appropriate query. However, in most cases the user needs several steps in order to find the searched objects. The main reasons for this are on the one hand, the problem of users to specify their interests in the form of a well defined query (which is partially caused by inappropriate user interfaces), on the other hand, the problem of extracting relevant features from the (multimedia) objects. To improve today’s retrieval tools and thus the overall satisfaction of a user, it is necessary to develop methods that are able to support the user in the search process, e.g. by providing additional information about the search results as well as the data collection itself and also by adapting the retrieval tool to the users needs and interests. I implemented different tools and applications.

CARSA is a web services based architecture, which supports the development of context based information retrieval systems. The idea of these systems is to support users in the search process by, e.g., adapting the search results as well as the interface itself to user specific needs and interests. CARSA's data and program structure was designed based on web services and XML. This allows to easily integrate and combine different methods to search data locally or on the web (meta-searcher functionality), to modify or categorize search results, and to develop visualization methods on diverse clients (e.g. desktop PCs or mobile devices). In addition, CARSA contains a testing environment for evaluating single methods, e.g. classification or clustering methods, or their combinations with standard performance measures on benchmark data sets.
In the research group in Magdeburg, I contributed in designing and implementing the system architecture. Furthermore, I designed my own plug-ins for indexing, categorizing and visualizing information.

I implemented the RDF/OWL LexiRes as a visualization tool for handling structures of ontological and lexical databases. The main idea of this tool is to give authors the possibility to navigate ontology hierarchies in order to restructure them, by manual or automatic merging, adding or deleting word senses. The tool is implemented in Java and uses the Jena Semantic Web Framework for querying and retrieving lexical data.

MultiLexExplorer is a tool that combines a knowledge-driven word sense disambiguation with a knowledge-based text retrieval approach in an interactive framework. Lexical resources are used in order to disambiguate documents (retrieved from the web or a local document collection) given the different meanings (retrieved from the lexical resources, in our case EuroWordNet) of a search term having unambiguous description in different languages. The focus is especially on the integration of methods that support the adaptation of the system interface and the output to the current search context. This tool has been a joint work with a student, who concluded then his diploma-thesis on this task.

The Multilingual Sense Folder Interface is an interface for supporting users in an interactive semantic-based search process. Semantic classes created from lexical resources are used for this purpose and combined with word sense disambiguation, multilingual text retrieval and document categorization techniques. The focus is on the problem of browsing and navigating information and the related different word senses of a query for filtering only the relevant documents related to these meanings. Moreover, the user is supported by named-entity recognition, spell checking and stemming methods. These components have been integrated in the user interface. I implemented this interface as a part of my doctoral thesis.